A significant explosive eruption occurred at 20:48 UTC July 2 (12:48 AKDT July 2). AVO is raising the Aviation Color Code to RED and Alert level to WARNING for Bogoslof volcano.

Satellite data and pilot reports shows a volcanic cloud with an estimated altitude of 36,000 ft asl moving towards the east. Seismic and infrasound data suggest that the ash emissions are no longer continuing.

(12) Volcanic cloud height:

36,000 ft asl estimated by satellite and pilot report

(13) Other volcanic cloud information:

Cloud moving towards east

(14) Remarks:

The SIGMET warning message for aviation, issued by the National Weather Service Alaska Aviation Weather Unit, currently is in effect up to 36,000 ft above sea level. Status of the ash cloud forecast can be found at their website at http://aawu.arh.noaa.gov/

Satellite data and pilot reports shows a volcanic cloud with an estimated altitude of 36,000 ft asl moving towards the east. Seismic and infrasound data suggest that the ash emissions are no longer continuing.

Remarks: The SIGMET warning message for aviation, issued by the National Weather Service Alaska Aviation Weather Unit, currently is in effect up to 36,000 ft above sea level. Status of the ash cloud forecast can be found at their website at http://aawu.arh.noaa.gov/

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

VOLCANO ALERT LEVELS

NORMALVolcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.

ADVISORYVolcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

WATCHVolcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway but poses limited hazards.

WARNINGHazardous eruption is imminent, underway, or suspected.

AVIATION COLOR CODES

GREENVolcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.

YELLOWVolcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

ORANGEVolcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway with no or minor volcanic-ash emissions [ash-plume height specified, if possible].

REDEruption is imminent with significant emission of volcanic ash into the atmosphere likely OR eruption is underway or suspected with significant emission of volcanic ash into the atmosphere [ash-plume height specified, if possible].